Vehicle and Drive Mechanism

ABSTRACT

Drive mechanism including a traction portion, a drive-receiving portion and a driven portion. The traction portion encircles and is rotatable about an axis. The drive-receiving portion encircles the axis and is fixed to rotate with the traction portion. The driven portion engages the drive-receiving portion to drive the traction portion to rotate. The traction portion is moveable relative to the driven portion to a plurality of positions along the axis. At least one of the drive-receiving portion and the driven portion has a length along which it is engageable by the other of the drive-receiving portion and the driven portion such that the drive-receiving portion and the driven portion co-operate to drive the traction portion at its plurality of positions along the axis.

CROSS REFERENCE TO RELATED APPLICATION

This invention claims the benefit of priority to Australian Provisional Patent Application 2012904776 filed Nov. 1, 2012, the entire disclosure of which is incorporated by reference.

FIELD

Various aspects of the invention relate to drive mechanisms and vehicles, and to components therefor.

The invention will be described with respect to an articulated boom lift for rail applications, although various embodiments of the invention may be suited to other applications.

BACKGROUND

An articulated boom lift is a vehicle 1 including a boom 2 carrying a work platform 3. A work platform is a platform on which a worker may stand. The boom 2 is articulated to allow the work platform 3 to be moved about within its service envelope 4. The boom 2 is pivotally mounted to a chassis 5 to permit rotation about vertical axis 6 so that a worker carried by the platform 3 can access and work on structures in the vicinity of the vehicle 1.

Other forms of elevatable platforms exist. By way of example, the boom 2 may be replaced by a scissor-lift mechanism.

Vehicles carrying elevatable platforms are useful for accomplishing overhead tasks such as trimming trees and repairing overhead wires. Various existing vehicles include road-engaging wheels 7 for running along a roadway to position the vehicle 1.

“Roadway” as used herein refers to a more or less planar surface along which a vehicle may run. The roadway surface may bituminous or cementitious or, for example, unsealed gravel.

Railways frequently require overhead maintenance, particularly those railways in which the trains are powered via overhead power lines. For the purpose of this maintenance, various vehicles having elevatable work platforms and rail-engaging wheel arrangements have been proposed.

It is not admitted that any of the information in this patent specification is common general knowledge, or that the person skilled in the art could be reasonably expected to ascertain or understand it, regard it as relevant or combine it in any way at the priority date.

SUMMARY

The present inventor has recognised that it would be useful to provide a vehicle adapted to run along a roadway in one mode of operation, and to run along rails in another mode of operation. Also, it would be useful to provide a vehicle which may run along rails of differing gauges. “Gauge” as used herein refers to the lateral spacing of the rails of a railway. A drive mechanism is disclosed, various embodiments of which are suited to a gauge-adjustable vehicle, whilst other embodiments of the drive mechanism may suit applications unrelated to vehicles.

One aspect of the invention provides a drive mechanism including

a traction portion encircling and rotatable about an axis;

a drive-receiving portion encircling the axis and fixed to rotate with the traction portion; and

a driven portion for engaging the drive-receiving portion to drive the traction portion to rotate;

wherein the traction portion is moveable relative to the driven portion to a plurality of positions, relative to the driven portion, along the axis; and

at least one of the drive-receiving portion and the driven portion has a length along which it is engageable by the other of the drive-receiving portion and the driven portion such that the drive-receiving portion and the driven portion co-operate to drive the traction portion at its plurality of positions, relative to the driven portion, along the axis.

The traction portion is preferably the periphery of a wheel for engaging a rail. The driven portion is preferably the periphery of a wheel for engaging a roadway. The drive-receiving portion is preferably the periphery of a friction drum.

Another aspect of the invention provides a vehicle including the drive mechanism. The vehicle preferably includes a vehicle body carrying a retro-fit module wherein the vehicle body carries the driven portion; and the module includes the traction portion and the drive-receiving portion.

Preferably the vehicle includes a control system including a user interface from which a user can control locomotion of the vehicle, wherein the control system has at least two modes and is configured to

when in a first of the modes, rotate the driven portion in a first direction in response to a user input; and

when in a second of the modes, rotate the driven portion in a second direction in response to the same user input.

Another aspect of the invention provides a module attached or attachable to a vehicle,

the vehicle having wheels for running along a roadway,

the module including a gauge adjustable arrangement of wheels for engaging and running along rails.

Preferably the vehicle includes a drive system for driving at least on the wheels for running along the roadway; and the arrangement of wheels includes at least one wheel driven by power drawn from the drive system. Most preferably the power is mechanically drawn.

Preferably a friction drum is fixed to rotate with the at least one wheel and arranged to be driven by at least one of the wheels for running along a roadway.

Another aspect of the invention provides a vehicle including the module.

Preferably the vehicle includes an elevatable work platform, and most preferably a or the user interface from which a user can control locomotion of the vehicle is associated or associable with the work platform for controlling from the work platform locomotion of the vehicle.

Another aspect of the invention provides a vehicle, for travelling along rails, including

an arrangement of wheels for engaging the rails;

an elevatable work platform; and

a user interface associated with the work platform for controlling from the work platform locomotion of the vehicle;

wherein the arrangement of wheels is gauge adjustable.

Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

The figures illustrate various exemplary features.

FIG. 1 is an elevation of an articulated boom lift and its operating envelope.

FIG. 2 is a plan view of an articulated boom lift.

FIG. 3 is an elevation of an articulated boom lift.

FIG. 4 is a front view of selected components of the articulated boom lift of FIGS. 2 and 3.

FIG. 5 is an elevation of the components of FIG. 4.

FIG. 6 is a front perspective view of the components of FIG. 4.

FIG. 7 a is an elevation of an articulated boom lift.

FIG. 7 b is a plan view of an articulated boom lift.

DESCRIPTION OF EMBODIMENTS

Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.

FIGS. 2 and 3 illustrate an articulated boom lift including an existing road-going articulated boom lift 12 and a pair of retro-fitted rail wheel modules 14.

Vehicle 10 includes four ground-engaging wheels 16. Each ground-engaging wheel 16 includes a metallic rim wrapped in a rubber tyre. The vehicle 10 further includes a drive system including a pump driving pressurised fluid to a respective hydraulic motor associated with each wheel 16. The drive system is configured to failsafe such that hydraulic pressure is required for the hydraulic motors, and their wheels, to rotate. In the event of a leak in the hydraulic system, the wheels are braked such that they do not rotate and the vehicle 10 does not run away.

Each module 14 includes a pair of rail-engaging wheels 18 mounted to rotate about a common axis A. Each wheel 18 has a nominal diameter of 350 mm and a profile to ANZR1 modified for use with an excavator. The wheels 18 are formed of 4140 to AS1444-2007-4140 and flame hardened for increased wear life.

Each wheel 18 includes a more or less cylindrical outer periphery (concentric to the axis A) forming a traction portion 18 a for bearing on the top surface of a respective rail to support and horizontally drive the vehicle 10. Each wheel 18 further includes an annular flange 18 b projecting radially outwards from an inboard side of the wheel. The flange 18 b serves to engage an inner side of that wheel's rail so that the vehicle 10 remains laterally aligned with the rails.

Each wheel 18 a carries a respective friction drum 20 on its outboard side. Each friction drum 20 has a cylindrical outer periphery concentrically aligned with the axis A, and so also to the wheel 18. This cylindrical periphery constitutes a drive-receiving portion 20 a. The drive-receiving portion 20 a is suitably textured to receive drive, e.g. with axially extending grooves as illustrated.

Turning to FIGS. 3 to 6, each module 14 includes a fixed portion 22 and a swing arm assembly 24. The fixed portion includes upright plates 22 a parallel to, and spaced across, the length of the vehicle 10. The plates 22 a are rigidly connected by cross-members 22 b. The fixed portion 22 is fixed to the body of the vehicle 12. In this embodiment the plates 22 b are welded to chassis rails 12 a of the vehicle 12, or alternatively they may be bolted on.

Desirably, this exemplary module is a retro-fit unit, i.e. it is built for attachment to a pre-existing vehicle rather than being built as an integral part of the vehicle. Accordingly the modules can be sold separately from vehicles to upgrade existing road-going vehicles.

The swing arm assembly 24 includes a pair of swing arms 24 a pivotally connected to the fixed portion 22. Each swing arm 24 a includes parallel plates spaced to embrace a portion of a respective one of the plates 22 a in the manner of a yoke.

The swing arms 24 carry a square tubular section 24 b at a distance from their common pivot axis. The tubular section 24 b extends horizontally across the vehicle 10.

Each wheel 18 is journalled to a respective stub axle (not shown) having a square cross-section dimensioned for sliding receipt within the tubular portion 24 b.

Each wheel 18 and stub axle subassembly has a respective hydraulic ram 26 acting between that stub axle and the tubular member 24 b to horizontally drive the subassembly to move the wheel 18 along the axis A to suit a desired gauge. FIGS. 2 and 4 to 6 illustrate alternative ram locations. In FIG. 2 the rams are mounted fore and aft of the section 24 b. In FIGS. 4 to 6 both rams of each module are mounted inboard of the tubular section 24 b. This inboard location protects the rams from damage due to obstacles between the rails. Locking pins are inserted into aligned apertures in the wall of the section 24 b and in the stub axle to lock the axle at a selected gauge.

In the example of FIG. 2, each wheel 18 has its own ram 26 such that the wheels 18 are outwardly advanced (or inwardly retracted) symmetrically. It is also contemplated that workable embodiments of the invention may be one-sided in that only the wheels on one side of the vehicle 10 move relative to the driven wheels 16.

A respective hydraulic ram 28 acts between each plate 22 a and its swing arm 24 a to pivotally raise and lower the wheels 18 (relative to the ground-engaging wheels 16) to suit roadway and railway operation respectively.

For the sake of illustration, the left hand side of FIG. 5 illustrates the swing arm assembly 24 in its raised position to suit roadway use. The right hand side of FIG. 5 illustrates the swing arm assembly 24 in its lowered rail-engaging position for railway use.

With reference to the left hand side of FIG. 5, it will be observed that the ground-engaging wheels 16 extend below the rail-engaging wheel 18, whereby when the ground-engaging wheel 16 is running along the ground the rail-engaging wheel 18 is lifted clear of the ground. It will also be observed that the rail-engaging wheel 18 (and in turn its friction drum 20) are spaced from the face of the wheel 16.

The right hand side of FIG. 5 shows the ram 28 in its extended position. The ram 28 has driven the swing arm 24 downwardly through an arc-shaped path (relative to the adjacent ground-engaging wheel 16). This motion serves to drive the rail-engaging wheel 18 into engagement with the rail and with continued advance of the ram 28 to lift the ground-engaging wheel 16 above ground and rail height. The wheels 16 are lifted about 100 mm above the rails 30. This motion also serves to drive the friction drum 20, or more specifically its drive-receiving outer periphery 20 a, to engage the ground-engaging wheel 16.

The wheels 16 bear on the friction drums 20 to rotationally drive the drums and in turn the wheels 18. The wheels 16, or more specifically their outer peripheries 16 a, constitute driven portions. The drive mechanism of the original vehicle 12 through its standard drive train, including the failsafe hydraulic motors, may thus drive the wheels 18 to drive the vehicle 10 along the rails 30.

Following this exemplary approach, the expense of a drive system dedicated to the rail wheels is avoided and the advantages of the failsafe operation are retained.

Typically the wheels 18, and the drums carried thereby, are moved to their desired lateral positions whilst the swing arm 24 is in its raised position. The friction drums 20 are about twice as long as they are wide. The cross-section of each drum 20 is in substance uniform along the drum's length whereby each wheel 16 may engage its drum at an infinity of selectable positions along its length. For the avoidance of doubt, this infinitely variable arrangement fits the description of “a plurality of positions” as those words are used herein. Of course it is also contemplated that in other variants the drive-receiving portions may co-operate with the driven portions at separate discrete axial positions; e.g. the friction drum may be replaced by discrete parallel gears.

A wide range of variants of the above mechanism is contemplated. By way of example, the elongate friction drums may be replaced by narrow drive-receiving wheels acting on elongate friction drums fixed relative to the ground-engaging wheels. The elongate friction drums fixed relative to the ground engaging wheels would preferably run parallel to the axis A. Indeed in some variants the rail-engaging wheels may engage directly with the ground-engaging wheels, e.g. the traction portions and the drive-receiving portions could be one and the same. In yet another variant, the friction drums 20 could be driven by a belt.

In operation the rail-engaging wheels 18 rotate in the opposite direction to the ground-engaging wheels 16. Thus preferred variants of the invention incorporate a control system that reverses the direction of rotation of the ground-engaging wheels 16 for a given user input, depending on whether the vehicle is in ground-running or rail-running modes. By way of example, the user input may be via a joystick or lever and it is desirable that a forward press of the lever cause forward motion of the vehicle 10 regardless of the vehicle's running mode.

Desirably a user interface 32 (FIG. 3), e.g. a joystick, is accessible from the work platform 3 whereby a single operator can control the locomotion of the vehicle 10 (in this example to control the vehicle 10 to move along the rails and along the ground) in addition to controlling the boom.

The control system could take the form of any suitable arrangement for converting user inputs into appropriate movements of the wheels 16, or command signals to the drive system. The control system could be wholly or partly integrated with the drive system and/or distributed across various portions of the vehicle 12.

When the vehicle 10 is set up to run along rails, and rails of differing gauges, its lateral footprint changes such that the boom orientation at which the vehicle 10 is at risk of toppling changes. Preferred forms of the control system incorporate safety interlocks responsive to the selected footprint of the vehicle 10 to adjust the permissible range of motion of the boom. Following this approach, the range of motion of the boom when the vehicle is on a horizontal roadway is not unduly restricted, and the vehicle is not at risk of toppling when located on a narrow gauge track. Again these safety interlocks may be implemented by any suitable means. By way of example, simple limit switches or more complex software-based approaches may be employed.

This exemplary vehicle may be operated as follows:

-   -   1. When the machine is in line with the rail tracks, the modules         14 can be lowered into position. While this operation is taking         place, other functions of the boom cannot be activated and the         brakes are in place. First only the front attachment can be         lowered. Once the friction drums are fully pressurised against         the tyre, only then the rear attachment can be lowered. This         ensures that the machine is braked at all times while the         attachments are being positioned. Once both the attachments are         in their respective positions, the functions for the rail mode         can be activated which are limited slew with full extension.     -   2. When the machine has to be taken out of the rail tracks, the         sequence is reversed. Only one attachment can be retracted at a         time while the other attachment stays in contact with the tyres         and the brakes are in the on position. This ensures that the         machine cannot roll away as at any given time the brakes are         applied either to the front tyres or the rear tyres.     -   3. When the rail attachment is not engaged, the boom can be used         on the ground as a normal machine.     -   4. There is a switch provided which has three modes, A, B and C.         In mode A, the machine acts as a normal ground machine and none         of the rail functions are available. In position B, the machine         is in setup mode for rail where, apart from the attachment         positioning, all other functions are not available. The machine         has to be in stowed position for mode B to be operated. In mode         C, the limited functions of the rail mode are available while         the attachments are locked in position. The attachments cannot         be operated either in mode A or mode C.     -   5. In rail mode, the machine drive is reversed through the         relays so the joystick functions remain the same. The operator         can continue using the joystick to move forward and reverse as         in normal operation. The tyres will drive in the opposite         direction in hi-rail mode, thus keeping the direction of travel         the same as in normal operation. This takes out the possibility         of driving in the wrong direction. The operator does not have to         alter the way he is driving the machine in any mode.

Interlock controls Mode A Description On Off Restrict On Restrict Off Rail function Extend Retract x Rail function side shift x (Broad/stand) Drive forward x Drive reverse x Steer left & right x Slew function x Boom extension x Primary, Secondary & jib booms x Basket level & rotate x

Interlock controls Mode B Description On Off Restrict On Restrict Off Rail function Extend Retract x Rail function side shift x (Broad/stand) Drive forward x Drive reverse x Steer left & right x Slew function x Boom extension x Primary, Secondary & jib booms x Basket level & rotate x

Interlock controls Mode C Description On Off Restrict On Restrict Off Rail function Extend Retract x Rail function side shift x (Broad/stand) Drive forward x Drive reverse x Steer left & right x Slew function x Boom extension x Primary, Secondary & jib booms x Basket level & rotate x

With reference to FIGS. 7 a and 7 b, key specifications of this exemplary vehicle are:

Measurements Weight 8,500 kg 18740 lbs Working height maximum 16.07 m 52 ft 2 in Platform height maximum 14.07 m 46 ft 2 in Horizontal reach maximum 7.65 m 25 ft 1 in Horizontal reach to side 5.2 m 17 ft 1 in Up and over clearance maximum 7.16 m 23 ft 6 in A. Platform length 0.76 m  2 ft 6 in B. Platform width 1.83 m  6 ft C. Height - stowed 2.11 m  6 ft 11 in D. Length - stowed 6.83 m 22 ft 5 in E. Width 2.29 m  7 ft 6 in F. Wheelbase 2.03 m  6 ft 8 in G. Ground clearance - center 0.39 m  1 ft 3.5 in

Productivity Lift Capacity 227 kg 500 lbs Platform rotation 160° Vertical Jib rotation 135° Turntable rotation 50° from Centre Line Turntable tailswing Zero Drive speed - stowed No Rail Engaged 8 km/h   5 mph Rail Engaged 5 km/h  3.1 mph Drive speed - raised 1 km/h 0.61 mph Gradeability 4WD - stowed 45% Rail Engaged - stowed* 25% Turning radius - inside 1.70 m  5 ft 6 in Turning radius - outside 4.50 m 14 ft 9 in Controls 12 V DC proportional Tyres - RT Lug - Foam Filled 355/55 D625

Power Power source Deutz diesel D2011L03i 3 cylinder disel 35.8 kW (48 hp) Auxiliary power unit 12 V DC Hydraulic tank 90.8 L 24 gal capacity Fuel tank capacity 64.4 L 17 gal

Standards Compliance ANSI A92.5, CSA B354.4, EN 280, AS 1418.10

While the above description refers to various examples, it will be appreciated that other embodiments can be adopted by way of different combinations of features. Such embodiments fall within the spirit and scope of this invention.

While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended. 

1.-13. (canceled)
 14. A vehicle, for in one configuration running along rails and in another configuration running along roadway, including a gauge adjustable arrangement of wheels for engaging the rails; an arrangement of wheels for engaging the roadway; a drive system for rotationally driving at least one of the wheels; a user interface for controlling the drive system; and an elevatable work platform; wherein the user interface is associated with the work platform for, in both of the configurations, controlling from the work platform locomotion of the vehicle; the at least one driven wheel is at least one of the roadway-engaging wheels; a portion of or fixed to rotate with the at least one driven wheel is engageable with a portion of or fixed to rotate with at least one of the rail-engaging wheels to rotationally drive the at least one rail-engaging wheel; and at least one of the portions of or fixed to rotate has a length along which it is engageable with the other of the portions of or fixed to rotate to so rotationally drive the at least one rail-engaging wheel when that wheel is at a plurality of positions to suit differing gauges.
 15. The vehicle of claim 14 wherein the portion of or fixed to rotate with at least one of the rail-engaging wheels has a length along which it is so engageable.
 16. The vehicle of claim 15 wherein at least one of the portions of or fixed to rotate is a friction drum.
 17. The vehicle of claim 14 including a vehicle body carrying a retro-fit module wherein the vehicle body carries the at least one driven wheel; and the module includes the at least one rail-engaging wheel.
 18. The vehicle of claim 14 wherein the user interface has at least two modes and is configured to 1) when in a first of the modes, rotate the at least one driven wheel in a first direction in response to a user input; and 2) when in a second of the modes, rotate the at least one driven wheel in a second direction in response to the same user input.
 19. The vehicle of claim 14 including a ram for driving the portion of or fixed to rotate with at least one of the rail-engaging wheels to engage with the portion of or fixed to rotate with the at least one driven wheel.
 20. The vehicle of claim 14 including a ram for driving at least one of the rail-engaging wheels to adjust the gauge of the arrangement of the rail-engaging wheels. 